Using Keyword tag searches in folder view does not work.

Why do keyword tags work differently in pse10 compared to version 7?
Keyword search appears to work differently depending whether one is in Thumbnail view or folder locaton view.
For example, searching on a 'flower' tag when in a sub-folder produces no results unless there are any flower images in that sub-folder. However if I switch to thumbnail view there are many results from other folders and it is clear that the system has searched right accross My Pictures and found all tagged images but will not display them in folder view.
This makes life very difficult because I keep images in Year folders so if I want to see all the images of , for example, a river, that I have taken over last 3 years I have to switch to thumbnail view to see them all.